To think if you arrange a meal

[Familyiness]

So it's my kids dad's birthday, all good.
Their dad's partner arranged a meal get together at a restaurant for him and invited my kids, still good.
Then she proceeds to put my eldest on the spot by asking if she is going to pay for her dad's meal?
I mean surely as she arranged it, she should pay for his meal.
This is not the first time she has done something like this. She wanted my daughter to buy her dad the expensive aftershave 90quid or something so she could buy the cheaper one.
I mean I'm getting very annoyed, and so is my daughter.
Are we being unreasonable or is she?

I agree - I posted that before OP said the ages of her children.

@Bellyblueboy they were 17, her birthday is dec, so she is 18 in a few weeks time and 21 and our son chipped in too, they also went on the holiday. He didn't ask them to, they arranged it for his 50th birthday and split the cost. They surprised him with it.
He can be a complete twit, last Christmas he was very ungrateful and Hurt my youngests feelings by pulling a face at the present she bought him.
This is why he is an ex, he is selfish, and never thinks.
Both myself and my eldest daughter told him he was out of order. But he still didn't get it. Still thinks its acceptable to be ungrateful, whilst I teach them to be grateful for anything.
He has always made minimal effort, I suspect as they get older they will see him less and less.
They are well suited as both him and her are pretty selfish.
My dh, and I constantly go without to ensure the kids are well cared for and he would never go without ever.
I don't like putting them in the middle even though they are now adults, but sometimes I have to get involved when something unfair crops up.

OP, you keep saying your dd is 'polite' but you can be polite and assertive at the same time. Teach her how to be assertive, it is a valuable life lesson.

Was we married to the same man!

This is exactly the same situation my teenagers have when they go out for dinner with their dad and his wife, only it’s their dad himself demanding they pay for his meals. I think he still believes he should be treated the same as when he was a child/teenager and was very spoilt. Doesn’t like to give the same back to his children though. He’s very tight, pays the minimum child maintenance he can get away with as he’s self employed. The children now choose to spend as little time with him as possible so you reap what you sow.

People like this will never believe they are in the wrong even if you point out their behaviour. Doesn’t mean you shouldn’t of course but in my experience it doesn’t change anything.

She needs to work on this and this can be a good learning moment.

No one should ever ask another person to pay a whole bill unless this has been pre-arranged. So it's perfectly polite to just reply "no, I won't be paying it all - let's split the bill (excluding birthday boy)".

If it was my birthday and this happened I'd look my partner in the eye and tell him/her not to be ridiculous.
Next time the 'kids' get invited they'll need to ask what they will be expected to pay for.
Impressed they managed to treat their Dad to trip to Turkey at 22!! I wouldn't have been able to pay for myself to go at that age!

@mondaytosunday tbh it was between 3 of them. They all paid a portion for themselves and their dad each month. And tbh for her age 22 year old has a good job earning decent money. She's on around 30grand atm and is up for a promotion which will take her past 40. And she lives at home so doesn't have too much to pay out. She also had another holiday to Turkey in Sept with her bf and friends. She travels the country going to concerts etc. Might aswell enjoy it whilst she has no real responsibilities.

@Keeptbreathing Oh he hates being critiqued but will happily do it to everyone else including his own kids. He moans about them and honestly there not bad at all. No police at the door, no drugs, no teen pregnancies so far, no big issues with them at all, usual teenage behaviour, bit stroppy at times.
I told him more than once he should be grateful for how good they are.
My daughters are like me, generous to a fault, almost too helpful to those who mostly don't deserve it.
I'm just now learning how to say no, and that's because of my illnesses I've had too.

I used to be “too polite” and say nothing to advantage takers. I wasted too much of my life people pleasing.

Although she’s young, this is a great time for her to start building her boundaries for the future. A good conversation to have might be along the lines of, “If that happens in future, what could you say in response to assert your own boundaries?”

Personally, if prepared, I would respond “I assumed as you organised this meal that you were already offering to do that. You gave me no indication in our previous conversation that you would expect me to.”

Followed by either: “I’m afraid I can’t afford to cover the unexpected expense. Please ask me in future rather than putting me on the spot, and creating such an uncomfortable atmosphere. Sorry, dad.”

Or: “Although you didn’t inform me previously of your expectations, I can afford to cover the cost of dad’s meal today, so yes, I will. For future reference though, please ask me ahead of the event, rather than putting me on the spot and creating an uncomfortable atmosphere. For all you knew I might not have been able to do that today, and this conversation would have been doubly uncomfortable for myself and my dad. Thanks.”

@CherryBlossom321 yes we have discussed what to do in future. But her dad was unaware as she asked her in the car whilst her dad wasn't in the car. So it was done sneakily.
Her dad already told her he didn't even want the meal in the first place

You can speak to the Dad, but I think you said you already did that, and it had no effect.
You have to train your girls to say no. No, I can't afford it; no, I've already bought Dads present.
It's horrible that he's treating them like this, but it's a good life lesson to learn to say no clearly and politely.
Doing it by text is easier than in person.

That is a fab response!

Ah, I see. In a sense, that’s even easier to deal with: “No, I’m not paying for dad’s meal as you arranged it so it’s safe to assume you’ve already planned to pay. Let me know in advance in future if that’s your expectation and we can discuss ahead of the event.”